Latest News: Forums Cruising Fitting a Secumar

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  • #3725
    Anonymous
    Inactive

    How should one fit a Secumar automatic bouyancy device?

    The advice in the forum is to mount a Secumar on a lanyard. Does that mean fitting a cheek block at the top of the mast and having a dedicated line running from mast foot to mast head, on the outside of the mast? Is the lower end of the Secumar bag just retained by the lanyard? If so, do they flap around much?

    Is the cheek block arrangement more-or-less the same technique as fitting a topping lift?

    Would it be ok to do both, or would so many fittings at the mast head weaken it?

    I am nervous about drilling into the mast (the same nervousness applies to the boom) for the self-tapping screws, although I have fitted a wind indicator. Is my nervousness unnecessary?

    The interest in Secumars is because I was out single handed on Saturday and capsized. I was quite shaken by this event, as I was a long way from the club and safety boats, and not dressed for immersion in May. Fortunately I got help from a passing fishing boat, otherwise I don’t know how I would have got back into the boat when I did get it up.

    Conditions were delightful, not extreme at all, so I was very surprised!

    I have a Mark 2, and it immediately inverted as far as it could. The water was relatively shallow, and the mast hit the mud on the bottom to stop it going right over.

    Since Saturday I’ve spent a while reading the posts on capsizing and inversion, and although I was firmly of the opinion that Wayfarers are hard to capsize, Saturday’s surprise has made me think a bit.

    The advice of the community will be much appreciated, as always.

    By the way, is there any interest in a discussion of why capsizes have occurred? I have a theory about mine that might be of interest …

    #6898
    Anonymous
    Inactive

    You have the right idea, a cheek block at the top of the mast with a lanyard running to a 8 cleat at the bottom. The Secumar is tied at both ends so it doesn’t flap too much, rearming is a problem at sea because it is very difficult to dry the device out. When you do capsize the device will hold the mast head about 6inches below the suface, so it is still possible to bring the boat into wind before righting, being on a lanyard means it is very easy to fit when you want it. I don’t use mine on our lake but always at sea or if there is a lack of safety cover.

    #6900
    Anonymous
    Inactive

    Thanks Simon – the capsize was less traumatic because the cruising conference had sensitised me to tie more things on than usual …

    #6901
    Dave Barker
    Keymaster

    Richard – out of interest, what are your thoughts about the cause of your capsize?

    #6903
    Anonymous
    Inactive

    It was basically not paying enough attention when the wind was directly opposed to the tide.

    I was trying to come up to a buoy for lunch, down wind and up tide. The correct technique is to do this just under head sail, but I had taken my genoa down some time before because I couldn’t control it properly (one of the jammers wouldn’t open – after the winter tune up!).

    So I was trying to see if I could slow the boat down while going directly downwind by sheeting the main in, thus reducing the area presented to the wind. It is supposed to work, but I think what happened in my case was that I was not completely sheeted in on a port tack when I altered course slightly to starboard to aim for my chosen buoy.

    The result was a gybe which I had not anticipated and had the main cleated (maybe there was gust as well). The boat broached, and I think that the turning moment of the sails one way, directly opposed by the tide running in exactly the opposite direction, was more than I could counter by moving my weight; over we went!

    That is my explanation for what happened.

    There is of course the lesson about cleating sheets, but when you sail single handed you have to some of the time, and as I say, the conditions were not extreme and not generally gusty.

    I think of more relevance to me is to awareness of the balance of forces between wind and tide, as I am very much learning about the effect of tide in dinghy sailing. I had had some very odd behaviour earlier when the boat simply wouldn’t tack through the wind, and I kept coming to a halt in irons. I think that was caused by the tide (up the transom) refusing to allow the bow to cross it. What I had to do was get far more way on before tacking than I would normally need, presumably so I could force my way against the lee bow effect to get the sail pulling on the other tack.

    Does that make sense?

    #6904
    Anonymous
    Inactive

    Leaving aside waves, the only effect the tide can have in open water is to affect the strength of the apparent wind. It can’t, in itself, capsize you or cause you to stick in irons etc. Fully understanding this is the key to managing conditions such as you describe.

    Imagine you were right out at sea, with no land for reference, yet there was (say) a 5kt current flowing against a 5kt wind. If you were drifting in a boat all you would have any awareness of would be a simple 10kt breeze, and whether this were caused by wind or tide would be entirely irrelevant. As long as you were sailing “normally” for a 10kt breeze then everything would happen normally – tacks, gybes, upwind, downwind.

    Now transpose that situation to more restricted waters, where you can see lots of other points of reference such as shoreline, moored boats, buoys etc. Nothing has changed, yet now you are very much aware of the effect of the tide relative to the ground, and it is extremely easy to be completely misled.

    For instance if sailing close-hauled with a tide assisting you, it is easy to think you are travelling faster through the water than you are. All your frames of reference might tell you that you are doing 7 kts, yet 5kts of this is perhaps due to the tide so in reality you are actually pinching along at 2kts, and thus when you try to tack the boat stops dead. But this isn’t because the tide is acting like some giant hand swinging the boat around, it is simply because you are sailing too slowly. If we go back to the “open sea” example this wouldn’t happen, as your only frame of reference would be the water.

    So the trick is to concentrate on sailing relative to the wind and water, rather than relative to static objects, and having managed this just sail normally as if there were no tide and the boat will behave normally too.

    As regards the capsize, whilst I agree with the “theory” that sheeting the main in on a dead run will slow the boat down, and indeed have done just that for tactical reasons when racing, it’s not something I’d do in anything but very light conditions, and under no circumstances would I cleat it there. Doing this moves the centre of pressure of the mainsail much further back, giving the boat a strong tendency to turn into wind, and in this instance the lack of a headsail would make this even worse.

    Also remember that if you were stemming the tide then your actual boatspeed through the water would be significantly higher than it would have appeared to be with reference to (eg) the buoy.

    What I think happened next was simply a textbook broach. The boat drifted a few degrees away from it’s downwind heading, and the unstable rig accelerated this turning effect. As soon as it began to heel this would add even more to this and the boat would simply head into wind with such rapidity that sheer momentum would capsize it, without needing all that much wind.

    As you say, the ideal approach if the tide were very strong would be to sail dead downwind into it under genoa alone. The balance of the rig would then be tending to keep the boat stable and pointing downwind, and with a sail of smaller area.

    Alternatively, if approaching under main alone, perhaps the better idea would have been to sail past and come head to wind, then let the tide bring you up to the buoy, grab it and drop the sail pronto.

    #6914
    Jim.Byers
    Member

    I pop rivrted two “P” brackets at the top of the mast and fit the bag before raising the mast.Better an inflated bag than nothing while I head for land to re-arm it.Spare in watertight container.(must be fitted in dry conditions with dry hands).

    #6915
    Anonymous
    Inactive

    I used my secumar for the first time this week whilst out solo sailing in Langston Harbour. (fantastic sail by the way, beautiful weather – very sunny, plenty of wind – almost no other boats out, 1 reef in and 1 big smile 😀 )

    My secumar was fitted to a flag halyard going to the top of the mast, so secured top and bottom of the device, then both parts of the halyard secured low on the mast.

    I did find it flapped around a bit, so I am going to change this method, and rivet a couple of small hoops high up, and secure the secumar on the mast before going out. I shall probably include short heavy bunjy / shock cord between the secumar and the connector to give some tension to it.

    #6916
    Anonymous
    Inactive

    John

    All things are relative (except the speed of light)!

    I think you must be right about travelling quite fast by reference to fixed objects, when actually going quite slowly through the water, and thus not able to tack properly.

    I only very recently understood the benefits of lee bowing, which are explained in terms of the apparent wind arising from the movement of the water.

    If I understand correctly, what you are suggesting is that I was travelling much faster through the water than I realised, because I was watching the buoy, and a broach at that speed caused the capsize – is that it?

    Thanks for your input.

    As I said, I am still very much learning about tides and dinghies …

    #6917
    Anonymous
    Inactive

    @Richard6402 wrote:

    John

    All things are relative (except the speed of light)!

    I think you must be right about travelling quite fast by reference to fixed objects, when actually going quite slowly through the water, and thus not able to tack properly.

    The classic example is tacking against the tide up a river, where on one tack you can nearly sail along the river, and on the other tack you are nearly sailing straight across it. On the short tack your reference to the shore tells you (correctly) that the tide is taking you backwards, and your instinctive reaction is to pinch, which just makes it worse. On the other tack you tend to want to sail fuller, as then you appear to be making faster progress along the bank, against the tide. Both reactions are wrong – what you should do is sail in your “normal” close hauled manner on both tacks, and let the shore take care of itself! Very difficult to do, but try and look at the sails more, the shore less, and think about the heel of the boat, the feel of the tiller etc to give you a better feel of your speed through the water.

    I only very recently understood the benefits of lee bowing, which are explained in terms of the apparent wind arising from the movement of the water.

    A steady tide gives a steady apparent wind. This “mixes” with the real wind to give a new steady wind vector. Contrary to popular belief this effect of the tide on the wind doesn’t vary depending on which tack you are on.

    If I understand correctly, what you are suggesting is that I was travelling much faster through the water than I realised, because I was watching the buoy, and a broach at that speed caused the capsize – is that it?

    Whilst the tide may well have misled you about your boatspeed (again, well worth looking over the side to see what’s really happening), the point I was really trying to make was that sheeting the sail hard in on a run will make the boat inherently very unstable, and would equally easily lead to a capsize on a lake – the tide isn’t a direct factor in that.

    Assuming you were in the exact same situation again, needing to approach under main alone, try and remember that the tide can’t capsize you (not directly) but the wind can. Thus you need to approach the buoy in a way that allows you to depower the sail, in other words come head to wind as you grab the buoy. I agree that in a strong tide this can be hairy when you grab the buoy and put yourself in the middle of a battle between tide and wind!

    As I said, I am still very much learning about tides and dinghies …

    So are we all. I wouldn’t want to step in a boat with someone who said he’d now learned everything there was to know…! 😉

    #6922
    matoi
    Member

    Hi Richard! Hi everybody!

    Thanks for sharing the experience! All this on sailing in strong currents is very interesting.

    I have one question for you: do you remember in what position was your centerboard when you capsized?

    Thanks + best regards,

    Mato

    #6934
    Anonymous
    Inactive

    When picking up a mooring or coming alongside try using the strongest force ( Wind/Tide) as the brake

    #6939
    Anonymous
    Inactive

    Mato

    The centreboard was right down.

    If you bring the centreboard right up and capsize, what do you do then to get the boat up again? Do you have to swim in, put the centreboard right down and then swim round the other side to climb onto the board to get the boat up?

    Simon

    I seem to recall from my yacht sailing that the tide is almost always the stronger force where yachts are concerned, and when manoeuvring in close quarters the effect of the tide is far more important than the effect of windage. But thinking about that, it must be when manoeuvring under power – if the tide dominated the wind with the sails up, you could never sail anywhere!

    I think in exactly the same situation again, I would sail up tide of the buoy, drop the main, hoist the genoa as the tide took me up wind of the buoy, and then try the correct manoeuver of coming down wind, up tide under genoa alone, letting the genoa fly forward to spill wind and slow down when appropriate.

    Or get the outboard working and motor the last bit!

    #6940
    matoi
    Member

    Hi Richard,

    I have an impression that most capsizes happen when sailing downwind with too much plate down. In your case, the opposing tide must have made the situation even worse. Regarding diving underneath the inverted boat and pushing the plate up (normally meaning down) – it is exactly what I had to do on a occasion when the plate slid back into case in the process of righting, but I agree it is quite unpleasant and probably risky.

    Take a look at this funny video and pay attention to the position of the plate in each case of capsize (470 Croatian sailors):

    http://www.youtube.com/watch?v=nDToL593cmU

    Best regards,

    Mato

    #6945
    howard
    Member

    My secumar is hauled up using a haliard, and I attach the other end of the haliard to the base of the secumar, flag-like. I have managed to stop the device flapping by threading the up-haul haliard through the bowline tied to the bottom end of the device, better holding the bottom of the secumar into the mast. This way it can be raised and lowered without dropping the mast – I wanted to take the device off the boat when I wasn’t sailing to ensure that it remained dry.

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